Silicon carbide wafer plasma etching device and method

Abstract

The invention discloses a silicon carbide wafer plasma etching device and method, which relates to the field of semiconductor etching technology, and comprises a shell, a bottom of which is equipped with a plurality of universal wheels; a heat preservation component, which is fixed in the shell; an etching component, which is fixed in the heat preservation component and in which a wafer is placed through an external feeding device; a main air inlet pipe, one end of which passes through the shell and the heat preservation component and is connected to the etching component, and the other end of which is connected to an external air supply device; a sealing cover, which is hinged on the shell and is used to seal the etching component; the invention can reduce the temperature loss rate of the etching component through the heat preservation component, thereby ensuring the temperature stability in the etching component, and can perform various forms of etching on the wafer through the etching component, thereby improving the efficiency and accuracy of etching.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor etching, and in particular to a silicon carbide wafer plasma etching device and method. Background Art

[0002] Plasma etching is the most common form of dry etching. Its principle is that the gas exposed to the electron area forms plasma. The resulting ionized gas and the gas composed of released high-energy electrons form plasma or ions. When the ionized gas atoms are accelerated by the electric field, they will release enough force to tightly bond the material with the surface expulsion force or etch the surface.

[0003] Currently, when plasma etching is performed on wafers, plasma is evenly sputtered on the surface of the wafer to remove the oxide layer. However, while etching the oxide layer, the mask is also etched, resulting in a poor etching selectivity. In addition, when regular pattern etching is required, such as strip etching, mesh etching or dot etching pattern etching, the existing etching equipment has a low accuracy rate.

[0004] In view of the above problems, the present invention provides a silicon carbide wafer plasma etching device to solve the above problems. Summary of the invention

[0005] To achieve the above object, the present invention provides the following technical solution: a silicon carbide wafer plasma etching device, comprising:

[0006] A housing, a plurality of universal wheels being mounted on the bottom of the housing;

[0007] A heat preservation component, fixed in the shell;

[0008] An etching assembly is fixed in the heat preservation assembly, and a wafer is placed in the etching assembly through an external loading device;

[0009] A main air inlet pipe, one end of which passes through the shell and the heat preservation component and is connected to the etching component, and the other end of which is connected to the external air supply device;

[0010] A sealing cover, hinged on the housing, for sealing the etching assembly;

[0011] The heat preservation component comprises a base, an outer shell is fixed on the base, an inner shell is coaxially fixed in the outer shell, a heat preservation layer is arranged between the inner shell and the outer shell, and exhaust ports are opened on one side of the outer shell and the inner shell.

[0012] Further, preferably, the external gas supply equipment includes a control unit, a gas storage chamber and a mixing adjustment chamber, wherein the control unit is used to control the gas intake of the gas storage chamber and the mixing adjustment chamber, the gas storage chamber is configured in plurality, storing a plurality of different etching gases therein, and the plurality of gas storage chambers are all connected to the mixing adjustment chamber, and the mixing adjustment chamber is connected to the main air intake pipe.

[0013] Further, preferably, the etching assembly comprises:

[0014] The etching chamber has an air inlet on the top, and the air inlet is connected to the main air inlet pipe;

[0015] A bearing column, fixed at the bottom of the etching chamber, with a bearing plate fixed at its output end;

[0016] The auxiliary etching component is installed inside the etching chamber.

[0017] Further, preferably, a discharge port is provided on a side of the etching chamber close to the exhaust port, a one-way valve is installed on the discharge port, and the etching chamber and the inner shell are both connected to an external vacuum pumping device.

[0018] Further, preferably, the auxiliary etching component comprises:

[0019] The first bearing seat is configured as two and symmetrically fixed on one inner wall of the etching chamber;

[0020] A driving motor is fixed on one of the bearing seats;

[0021] A driving screw, rotatably disposed between the two bearing seats and driven by the driving motor;

[0022] A drive nut, threadedly connected to the drive screw;

[0023] The adjusting component is slidably arranged in the etching chamber, and one end of the adjusting component is fixedly connected to the driving nut.

[0024] Further, preferably, the adjustment component comprises:

[0025] A sliding plate, slidably disposed in the etching chamber and driven by the driving nut;

[0026] The second bearing seat is configured as two and symmetrically fixed to an end of the sliding plate away from the driving nut;

[0027] An adjusting motor is fixed on one of the bearing seats 2;

[0028] An adjusting screw, rotatably disposed between the two bearing seats 2, and driven by the adjusting motor;

[0029] An adjusting nut, threadedly connected to the adjusting screw;

[0030] An adjusting plate is arranged on the sliding plate by sliding a slider up and down, and is fixedly connected to the adjusting nut;

[0031] The adjusting rod is configured as a plurality of rods and is arranged on the sliding plate by sliding the slider left and right;

[0032] The nozzles are configured in multiple numbers, are fixed on multiple adjusting rods respectively, and are connected to external air supply equipment by using hoses.

[0033] Further, preferably, the adjustment plate is provided with a plurality of adjustment slots arranged in a fan shape, an adjustment roller is slidably arranged in the adjustment slot, and one end of the adjustment roller is rotatably arranged on the plurality of adjustment rods.

[0034] A method for using a silicon carbide wafer plasma etching device comprises the following steps:

[0035] S1. Wafer installation: Place the wafer on the carrier plate through an external loading device and close the sealing cover;

[0036] S2. Environmental adjustment: vacuum the etching chamber and the inner shell, respectively, and adjust the temperature in the etching chamber by an external temperature control device;

[0037] S3. Preliminary etching: etching gas is provided through the main air inlet pipe to perform preliminary etching on the wafer, and the etching process stops when the oxide layer etching progress reaches half;

[0038] S4. Secondary etching: secondary etching is performed through the nozzle of the auxiliary etching component to completely etch the oxide layer, complete the pattern to be etched, and take out the wafer through an external loading device.

[0039] Compared with the prior art, the present invention provides a silicon carbide wafer plasma etching device, which has the following beneficial effects:

[0040] In the present invention, double vacuuming is performed by evacuating the etching chamber and the inner shell separately, which can greatly reduce external interference and ensure the stability of the etching environment. During etching, preliminary etching can be performed through the main air inlet pipe to avoid a large degree of etching of the oxide layer and the mask, which affects the etching accuracy. After that, secondary etching is performed through the nozzle of the auxiliary etching component, and only the position that needs to be etched is accurately etched. The etching accuracy is improved by double etching, and when regular pattern etching is required, etching can be directly performed through the nozzle of the auxiliary etching component to improve etching efficiency. The spacing between the nozzles can be adjusted through the adjustment plate, so that etching operations can be performed on wafers with different requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the overall structure of a silicon carbide wafer plasma etching device;

[0042] Figure 2 It is a schematic diagram of the structure of an etching component of a silicon carbide wafer plasma etching device;

[0043] Figure 3 It is a schematic diagram of the structure of an adjustment component of a silicon carbide wafer plasma etching device;

[0044] Figure 4 This is a schematic diagram of the structure of an auxiliary etching component of a silicon carbide wafer plasma etching device;

[0045] Figure 5 A schematic diagram of a method for using a silicon carbide wafer plasma etching device;

[0046] In the figure: 1. shell; 2. insulation component; 3. etching component; 4. wafer; 5. main air inlet pipe; 6. sealing cover; 21. base; 22. outer shell; 23. inner shell; 24. insulation layer; 25. exhaust port; 31. etching chamber; 32. air inlet; 33. bearing column; 34. bearing plate; 35. auxiliary etching component; 351. bearing seat 1; 352. driving motor; 353. driving screw; 354. driving nut; 355. adjusting component; 3551. sliding plate; 3552. bearing seat 2; 3553. adjusting motor; 3554. adjusting screw; 3555. adjusting nut; 3556. adjusting plate; 3557. adjusting slot; 3558. adjusting rod; 3559. nozzle. DETAILED DESCRIPTION

[0047] Reference Figure 1-Figure 5 The present invention provides a technical solution: a silicon carbide wafer plasma etching device, comprising:

[0048] The housing 1 has a plurality of universal wheels mounted on the bottom;

[0049] A heat preservation component 2, fixed in the housing 1;

[0050] The etching component 3 is fixed in the heat preservation component 2, and a wafer 4 is placed inside the etching component 3 through an external loading device;

[0051] A main air inlet pipe 5, one end of which passes through the housing 1 and the heat preservation component 2 and is connected to the etching component 3, and the other end of which is connected to an external air supply device;

[0052] A sealing cover 6, hinged on the housing 1, for sealing the etching assembly 3;

[0053] The insulation component 2 includes a base 21, an outer shell 22 is fixed on the base 21, an inner shell 23 is coaxially fixed inside the outer shell 22, an insulation layer 24 is arranged between the inner shell 23 and the outer shell 22, and an exhaust port 25 is opened on one side of the outer shell 22 and the inner shell 23.

[0054] That is to say, the etching component 3 can be kept warm by the heat preservation component 2, thereby reducing the speed of temperature loss in the etching component 3, reducing energy consumption while maintaining the stability of the etching environment.

[0055] In this embodiment, the external gas supply equipment includes a control unit, a gas storage chamber and a mixing adjustment chamber, wherein the control unit is used to control the gas intake of the gas storage chamber and the mixing adjustment chamber, the gas storage chamber is configured in multiple numbers, and multiple different etching gases are stored therein, and the multiple gas storage chambers are all connected to the mixing adjustment chamber, and the mixing adjustment chamber is connected to the main air intake pipe 5.

[0056] Among them, the gas in the gas storage chamber contains the supply of various etching gases (such as carbon tetrafluoride, oxygen, etc.). The optimized ratio of the etching gas is achieved through the precise flow control of the control unit and the adjustment of the mixing ratio in the mixing adjustment chamber.

[0057] In this embodiment, the etching component 3 includes:

[0058] The etching chamber 31 has an air inlet 32 ​​on the top, and the air inlet 32 ​​is connected to the main air inlet pipe 5;

[0059] A carrying column 33 is fixed at the bottom of the etching chamber 31, and a carrying plate 34 is fixed at the output end thereof;

[0060] The auxiliary etching assembly 35 is installed inside the etching chamber 31 .

[0061] It should be noted that the bearing column 33 has lifting and rotating functions, which can be realized by a lifting motor and a rotating motor. The connection structure thereof is a prior art and will not be described in detail here.

[0062] That is to say, the supporting column 33 can drive the supporting plate 34 to be lifted and rotated, so as to adjust the position of the wafer 4 and cooperate with the auxiliary etching component 35 to accurately etch the wafer 4 .

[0063] As a preferred embodiment, a discharge port is provided on a side of the etching chamber 31 close to the exhaust port 25, a one-way valve is installed on the discharge port, and the etching chamber 31 and the inner shell 23 are both connected to an external vacuum pumping device.

[0064] As a preferred embodiment, the auxiliary etching component 35 includes:

[0065] The first bearing seat 351 is configured as two and symmetrically fixed on the inner wall of one side of the etching chamber 31;

[0066] A driving motor 352 is fixed on one of the bearing seats 1 351;

[0067] A driving screw 353 is rotatably disposed between the two bearing seats 1 351 and driven by the driving motor 352;

[0068] A driving nut 354, threadedly connected to the driving screw 353;

[0069] The adjustment component 355 is slidably disposed in the etching chamber 31 , and one end of the adjustment component 355 is fixedly connected to the driving nut 354 .

[0070] As a preferred embodiment, the adjustment component 355 includes:

[0071] A sliding plate 3551 is slidably disposed in the etching chamber 31 and driven by the driving nut 354;

[0072] The second bearing seat 3552 is configured as two and symmetrically fixed to an end of the sliding plate 3551 away from the driving nut 354;

[0073] An adjusting motor 3553 is fixed on one of the bearing seats 2 3552;

[0074] The adjusting screw 3554 is rotatably disposed between the two bearing seats 3552 and driven by the adjusting motor 3553;

[0075] An adjusting nut 3555, threadedly connected to the adjusting screw 3554;

[0076] The adjusting plate 3556 is arranged on the sliding plate 3551 by sliding a slider up and down, and is fixedly connected to the adjusting nut 3555;

[0077] The adjusting rods 3558 are configured as a plurality of rods and are arranged on the sliding plate 3551 by sliding a slider to slide left and right;

[0078] The nozzles 3559 are configured in plurality and are respectively fixed on the plurality of adjusting rods 3558 and connected to the external air supply device by a hose.

[0079] That is to say, the nozzle 3559 can be adjusted in the XY axis direction through the driving motor 352 and the adjusting motor 3553, and the wafer 4 can be adjusted in the Z axis direction through the supporting column 33, so as to facilitate the nozzle 3559 to etch various patterns.

[0080] It should be noted that the adjustment motor 3553 can not only adjust the position of a single nozzle 3559, but also adjust the spacing between multiple nozzles 3559, so that regular patterns can be etched quickly.

[0081] As a preferred embodiment, a plurality of adjustment slots 3557 arranged in a fan shape are provided on the adjustment plate 3556 , an adjustment roller is slidably arranged in the adjustment slot 3557 , and one end of the adjustment roller is rotatably arranged on the plurality of adjustment rods 3558 .

[0082] A method for using a silicon carbide wafer plasma etching device comprises the following steps:

[0083] S1. Wafer 4 is installed by placing the wafer 4 on the carrier plate 34 through an external loading device, and the sealing cover 6 is closed to ensure the vacuum environment in the etching chamber 31;

[0084] S2. Environmental adjustment: vacuuming the etching chamber 31 and the inner shell 23 respectively, and adjusting the temperature in the etching chamber 31 by an external temperature control device. By vacuuming the etching chamber 31 and the inner shell 23, double vacuuming is achieved, which can greatly reduce external interference and ensure the stability of the etching environment;

[0085] S3. Preliminary etching, providing etching gas through the main air inlet pipe 5, performing preliminary etching on the wafer 4, and stopping when the etching progress of the oxide layer reaches half, that is, during etching, preliminary etching can be performed through the main air inlet pipe 5 to avoid a large degree of etching of the oxide layer and the mask, which affects the etching accuracy;

[0086] S4. Secondary etching, secondary etching is performed by the nozzle 3559 of the auxiliary etching assembly 35, the oxide layer is completely etched, the pattern to be etched is completed, and the wafer 4 is removed by an external loading device;

[0087] When regular pattern etching is required, etching can be performed directly through the nozzle 3559 of the auxiliary etching assembly 35 to improve etching efficiency, and the spacing between the nozzles 3559 can be adjusted through the adjustment plate 3556, so as to perform etching operations on wafers 4 with different requirements;

[0088] When etching is performed directly through the auxiliary etching assembly 35, multiple nozzles 3559 are synchronously fed with air, and when the auxiliary etching assembly 35 is a secondary etching operation, it is fed with air individually according to the etching pattern required by the wafer 4;

[0089] It should be noted that the process of converting etching gas into plasma during etching is a prior art, and its structure will not be described in detail here.

[0090] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A silicon carbide wafer plasma etching device, characterized in that: include: A housing (1) having a plurality of universal wheels mounted on its bottom; A heat preservation component (2) fixed in the shell (1); An etching component (3) is fixed in the heat preservation component (2), and a wafer (4) is placed in the etching component via an external loading device; A main air inlet pipe (5), one end of which passes through the housing (1) and the heat-insulating component (2) and is connected to the etching component (3), and the other end of which is connected to an external air supply device; A sealing cover (6) is hingedly connected to the housing (1) and is used to seal the etching component (3); The heat-insulating assembly (2) comprises a base (21), an outer shell (22) is fixed on the base (21), an inner shell (23) is coaxially fixed inside the outer shell (22), a heat-insulating layer (24) is provided between the inner shell (23) and the outer shell (22), and exhaust ports (25) are provided on one side of the outer shell (22) and the inner shell (23); The etching component (3) comprises: An etching chamber (31) is provided with an air inlet (32) on the top, and the air inlet (32) is connected to the main air inlet pipe (5); A carrying column (33) is fixed at the bottom of the etching chamber (31), and a carrying plate (34) is fixed at the output end of the carrying column; An auxiliary etching component (35) installed inside the etching chamber (31); The auxiliary etching component (35) comprises: Bearing seat 1 (351) is configured as two and symmetrically fixed on an inner wall of one side of the etching chamber (31); A driving motor (352) fixed on one of the bearing seats (351); A driving screw (353) is rotatably disposed between the two bearing seats (351) and is driven by the driving motor (352); A driving nut (354) threadedly connected to the driving screw (353); An adjustment component (355) is slidably disposed in the etching chamber (31), and one end of the adjustment component is fixedly connected to the driving nut (354); The adjustment component (355) includes: A sliding plate (3551) is slidably disposed in the etching chamber (31) and is driven by the driving nut (354); The second bearing seat (3552) is configured as two and is symmetrically fixed to one end of the sliding plate (3551) away from the driving nut (354); An adjusting motor (3553) is fixed on one of the bearing seats 2 (3552); An adjusting screw (3554) is rotatably disposed between the two bearing seats (3552) and driven by the adjusting motor (3553); An adjusting nut (3555) threadedly connected to the adjusting screw (3554); An adjusting plate (3556) is arranged on the sliding plate (3551) by sliding a slider up and down, and is fixedly connected to the adjusting nut (3555); The adjusting rod (3558) is configured as a plurality of adjusting rods, and is arranged on the sliding plate (3551) by sliding a slider to slide left and right; The nozzles (3559) are configured in plurality and are respectively fixed on the plurality of adjusting rods (3558) and connected to an external air supply device by means of a hose; The adjustment plate (3556) is provided with a plurality of adjustment slots (3557) arranged in a fan shape, an adjustment roller is slidably arranged in the adjustment slot (3557), and one end of the adjustment roller is rotatably arranged on the plurality of adjustment rods (3558).

2. A silicon carbide wafer plasma etching device according to claim 1, characterized in that: The external gas supply device comprises a control unit, a gas storage chamber and a mixing and regulating chamber, wherein the control unit is used to control the gas intake of the gas storage chamber and the mixing and regulating chamber, the gas storage chamber is configured as a plurality of gas storage chambers, wherein a plurality of different etching gases are stored therein, and the plurality of gas storage chambers are all connected to the mixing and regulating chamber, and the mixing and regulating chamber is connected to the main air intake pipe (5).

3. A silicon carbide wafer plasma etching device according to claim 1, characterized in that: A discharge port is provided on a side of the etching chamber (31) close to the exhaust port (25), a one-way valve is installed on the discharge port, and both the etching chamber (31) and the inner shell (23) are connected to an external vacuum pumping device.

4. A silicon carbide wafer plasma etching method, which uses a silicon carbide wafer plasma etching device as described in any one of claims 1 to 3, characterized in that: The steps include: S1. Installing the wafer (4), placing the wafer (4) on the carrier plate (34) by an external loading device, and closing the sealing cover (6); S2. Environmental adjustment: vacuuming the etching chamber (31) and the inner shell (23), respectively, and adjusting the temperature in the etching chamber (31) by an external temperature control device; S3. Preliminary etching, providing etching gas through the main air inlet pipe (5), performing preliminary etching on the wafer (4), and stopping when the etching progress of the oxide layer reaches half; S4. Secondary etching: secondary etching is performed through the nozzle (3559) of the auxiliary etching component (35), the oxide layer is completely etched, the pattern to be etched is completed, and the wafer (4) is taken out through an external loading device.

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